Powder for calibration solution Ph 4.01 + 6.86 + 9.18

Calibration of the pH meter :
1. Dissolve the calibration powder in 250 ml of distilled water or purified water. Dip the pH electrode into the standard solution and shake gently.
2. Remove the PH pen until the displayed value corresponds to the pH value of the standard value of the buffer solution at ambient temperature.
3. It is generally recommended to first tune 6.86 (neutral value) and then tune 4.01 to achieve a two-point correction, it will be more accurate!